A known artificial disc member is disclosed in U.S. Pat. Nos. 5,370,697. 5,370,697 discloses an artificial disc having upper and lower supports connected to adjacent vertebrae and an elastic separator. The separator has cover plates connected to opposite sides of an elastic core. The separator is a separate insert part that may be inserted between the upper and lower supports after the supports are connected to the vertebrae. The separator does not engage the vertebrae.